Hallee Sorenson, 18, was forced to sit alone at her birthday party last year after friends failed to show up.

Hallee’s cousin, Rebecca Guilford of Oxford, Mass., captured the photo and posted it on Facebook. The post has since gone viral, garnering over 159,000 shares.

Guilford says her cousin is a “beautiful young woman—both inside and out. She lights up a room with her smile. Hallee is funny, sweet, caring, smart, an athlete, a jigsaw puzzle champion, a wonderful student, and a best friend to all. Hallee is an amazing person-a person I am proud to be related to.

“She is also a person who just happens to have Autism,” Guilford said.

“Invitations went out to her classmates at school and to other friends in the area. Hallee sat at her party anxiously waiting for her friends to arrive so they could have fun….but Hallee’s friends would never arrive,” Guilford said about last year’s party.

Hence Guilford’s call to action:

“But you can help make this years birthday incredible!! I would love to flood her mailbox with birthday cards, from all over! Hal loves getting mail—this would be the best birthday gift she could ask for.”

Since then, the Facebook post has been stocked with replies from people who were moved by the story and promising to send Hallee a card.